Arc-lamp.



J. T. H. DEMPSTER.

ARC LAMP. v APPLIOATION FILED NOV.16, 1903. 1,091,641 Patented Mar. 3 1,1914.

2 SHEETS-SHEET 1.

INVENTQF-i. John T HDempst'n q ah M 1:1

J. T. H. DBMPSTER. ARC LAMP.

APPLICATION FILED NOV. 16, 1903. 1 091 641 Patented Mar. 31, 1914.

2 SHEETS-SHEET 2.

MTNESSES: v lm/ DR 4 1%? bJoHnTHUempsfen {MAM/Y UNTTEDF STATESPATEN '1()FFICE, 30m: '1. 1'1- nnmre'rnn, orsciinmicmny, NEW YORK, nssrcmon TOGENERAL nmcrmc (mumm A conronnrion or NEW YORK.

Also-LAMP.

To all who-m may concern:

Be it known that I, JOHN T. H. DEMP- s'rnn a citizen of the UnitedStates, residing at chenectady. county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Arc- Lamps,of which the following is a specification.

The object of my present invention is to improve the construction andoperation of arc lamps.

More particularly my invention relates to are lamps in which the majorportion of the illumination comes from the arc itself as distinguishedfrom those lamps in which the major, portion of the illumination comesfrom electrodes heated to incandescence. In

I such lamps it has been found that one of the electrodes canadvantageously be so constructed and arranged that it will not consumeduring the normal operation of the lamp, and my present inventioncontemplates a certain novel construction and arrangement of such anon-consuming elec trode.

My present invention also contemplates a novel electrode feed mechanism.This mechanism I have hereinafter illustrated and described as employedin a lamp provided with my novel form of non-consuming electrode, but itis not necessarily in all respects limited to such conjoint use.

These features of novelty, together with others which characterize mypresent invention, are pointed out wi 11 particularity in the claimsannexed to and forming a part of this specification.

For the better understanding of my in: vention reference may be had tothe annexed .drawings in which I have illustrated one embodiment of myinvention.

Of the drawings, Figure 1 is a sectional elevation of an arc lamp; Fig.2 is an-elevation showing part of the mechanism of the lamp; Fig. 3 is asimilar View taken at right angles to Fig. 2; Fig. 4 shows a de tail ofthe feed mechanism; Fig. 5 shows the bottom of the lamp casing and themethod of supporting the globe; Fig. dis a diagram illustrating thecircuits of the lamp, and Fig. 7 is' a perspective View 'of the manuallyoperated cross-head-for disengaging the clutch.

Referring to't-he drawings, 1 represents the lamp cap or top, on theupper side of Specification of Letters Patent. Application filedNovember 16, 1903i Serial No. 81,299;

which suitable supporting means are placed. Binding posts 3 and 3' ofordinary construction are also carried by the cap 1'. A tubular member45 is securedto the under side of the cap 1' by screws 4:. At the lowerend Patented Mar.31,1914f.

of the member 4 a disk-like platform 5 is carried. Posts 6 dependingfrom platform 5 carry at their lower ends another disklike latform 7.Some distance beneath the plat mm 7 an annular member 8 is carried bymeans of the screws 9 which are threaded into the under side of thelatform 7. A tubular member 8 extends ownward'from the inner peripheryof the annular member 8 for a purpose to be hereinafter set forth.

A circular plate 10, of some material, such as copper, which is a goodconductor of heat and electricity, is located in the space between theplatform 7 and the annular member 8. This plate is separated-andinsulated from the platform 7 and annulai; member 8 by means of thetubular spacing members 11 which surround the bolts or screws 9. Fromthe under side of the member 10 a cylindrical rod or pencil 13 extendsforming one of the electrodes of the lamp.

The rod or pencil 13 is made out of some material which is a goodconductor both of heat and electricity, such as copper, and is securedto the Plate 10 in any suitable manner, as by means of a threadedextension of the rod or pencil which is screwed into a threaded openingformed for the purpose in the plate 10. The electrode 13 passescentrally through the annular member 8 projecting below the annularmember about as far as does the tubular member 8. A jacket or layer letof mica, or similar material, surrounds the upper portion of the rod orpencil 13 extending down to within a short distance of the lower end ofthe pcncil. Another bushing or tube section 15 of substantially the samelength as the rodor pencil, and preferably formed out of porcelain,surrounds the mica jacket and inclosed pencil. It will be observed thatthe lower end of the pencil 13 is separated from the insulating jacketby an annular' space 15.

The lower electrode 16 of the lamp, which may be formed of, or contain,magnetite or titanium carbid, or other materialgiving a flaming orluminous arc, is held in a socket, 17 carried by a cross head 18. Thecross head 18 is secured to the lower end of a pawl. and carries v islimited by i pair of rods 19 which pass through apertures formed for thepurpose'in platform 7, annular member 8 and plate 10. Suit able bushings20 which may be formed out of porcelain or other insulating materialserve to insulate the rods 19 from the plate 10. cross head 18 unitesthe upper ends of the rods 19. The cross head 18' is secured to thelower end of a rack bar 21. The upperend of this bar isgadapted .toenter the tubular member 4 with which it cooperates; to form aregulating dashpot. A shaft 22', journaled in bearings 23-. carried bythe posts 6, carries a which meshes with the teeth on the rack 21. Theshaft also carries a ratchet wheel 2-1 somewhat larger than the gearwheel 24:.

A pair of magnet coils 26 are supported by a post or member 27 formed ofmagnetic material to which their cores 28 are connected by screws 29.The post 27 has an oiiset portion 28 at its lower end. which restsagainst the upper surface of platform 7. Screws 29 passing through theoffset portion of 28 secure it to the member 7. The armature 30 7; Aspring 33, having one end secured to a lag formed for the purpose on thepost 27 and the other end secured to a similar lug formed for thepurpose on the armature 30 below its support 31, normally holds thearmature in the position shown in Fig. 2. The outward movement of thearmature 30 a stop 34 which may consist of a projectionor extension ofone of the cores 28 which passes through a slot or channel formed forthe purpose in the armature 30 and is formed with a bend at its outerend,

spring pawl 35, the outer end of which normally engages the ratchetwheel 25, is secured to the upper end of the armature 30. A. member 36loosely pivoted to the armature 30 above the pawl 35 has near its freeend a slot indicated in dotted lines in Fig. 2, and the tooth of thepawl passes through that slot;-it also has an oll'set portion 87 at itsouter end. The'pawl 35 and member are so arranged .that when outer end37 of the member 36 is depressed, it engages the it out of engagementwith the teeth of the ratchet wheel 25. he teeth on ratchet wheel 25 andpawl 35 are so arranged that when themagnctcoils 26 are energized andthe arnmture ill is attracted the wheel 25 will be minted in thedireclion indicated --by the arrow in Fig. 2. /Vhcn the magnet coils 9,6are dciinerg'izwl the armature 30 will return to the position shown in2. A dog secured to the under side oi the platform :7 nm'mally preventsa. rotation of the ratchet wheel 25 in the direction opposite to thatindicated by the arrow in Fig. 2.

spur gear wheel 24 A spring contact member 39, secured in any suitablemanner to the under side of platform 5, is n'ormally in engagement withone'en'd of a contact screw 40 passing through a-member 41, also securedto the under side of platform An arm or member 42 projecting from thearn'iature 30 is adapted to engage the lower end of the member 39 andmove it out of engagement with the end of the screw 40 for a purpose tobe hereinafter set forth when the arl'nature 30 approaches the end ofthe core 28' under the action of the coils426.

A magnet coil 48 having its axis vertical is carried on the upper sideof the platform 7. The armature 44 which coiiperates with this magnetcoil is pivoted at one end to a post or member 45 carried on the upperside of platform 7. A helical spring 46, having one end secured to a.lug formed for the purpose on the upper side of the armature 4i and theother end secured to the lower end of a bolt 47' which is adjustablysecured to the platform 5, normally holds the ar1nature in the positionshown in Fig. l. The upward movement of the free end of the armature 44is limited by its engagement with a screw 48 carried by an arm 49, whichis secured to a block 50, carried in turn by an arm 51, which is clampedto two of the posts 6. A spring arm 52 is carried from the under side ofblock 50. The arm 52, by reason of its resiliency, normally bearsagainst an adjustable contact member 53 carried by the arm 49. The outerend of the spring arm 52 is extended so that it will be engaged by theouter end of the armature 44 in its downward movement occurrhig whenit1s attracted by the coil 43. The movement given to the arm 52 by thisdownwardmovement of the armature 4-4,- will cause the contact tolie-broken between the arm and the contact. member 53. A. redfalpivotally connected to the upper side of the armature l4, and havingits upper end guided by the platform 5 through an aperture in which itpasses, carries a pair of adjustable collars, 55 and 55. l Vhen thearmature 4.4- is at tractcd by the coil 43 and the rod 54. is moveddowi'nvard, the collar 55 will engage with dog 38, move it out ofengagement with the ratchet wheel 25, and at the same time the collar 55will engage the offset end 37 of the pivoted member 36 and through itmore the pawl 35 out of engagement with the ratchet wheel 25. thusfreeing the ratchet wheel 25 from its engagement with the dog 38 andpawl 35 for a purpose to be hereinafter determined.

A rod 56 extends upward from the plat form 7. The yoke member 5'? of aclutch surrounds this'rod. The voice member 57 has apawl 5d pivoted toit. The inner end or the pawl 15 sharpened and normally on gages the rod56, as is clearly shown in Fig.

'ing mechanism out the lamp.

3, by reasonof the. fact that the outer end overbalances the inner end.A rod 59 extends upward from the cross head 18 adjacent the rod 56passing through an aperture formed for the purpose in the outer end ofpawl 58. Collars and. (51 are adjust-ably secured to the rod 59 atopposite sides of the pawl 58. When the cross head 18' and thereby therod 59 is moved upward, the clutch 57 ollers no resistanceto themovement of the rod 59, the rod 59 passing loosely through the aperturein one end of the pawl until the underside of he pawl 58 is engaged bythe collar 61, at r which the upward movement of the cross head 18'carries the clutch 57 with it. The downward movement of the cross head18, and consequently of the electrode 16, is limited, however. by theengagement oi the collar (.10 with the upper side of the pawl 58; thisengagement causes. the pawl 58 to grip the rod 56 more firmly.

In order that the clutch 57 may be released from its engagement with therod 56 and the cross head 18' be lowered Whenever it heeomes desirableto do so, I have provided a cross head "2 of insulating materiel whichslides upon the run 56. This cross. heed mounted upon the upper end ofan tu'icrating XOll 63. The lower end of this rod passes throughapertures formed for the purpose in platform 7, annular memher 8 andplate 10 and is )rovidcd at its 7 lower end with button 6 by which itcan be grasped. .A catch normally holds the cross head 62 elevated inthe position shown in Fig. 3. Upon pulling this cross head'doun upon theyoke 51' the locking' engagement. between the clutch and the rod'filiwill be broken and the cross head 20 and parts connected thereto canthen be lowered.

1 cylindrical casing 66, which may be formed out of sheet metal. extendsbetween the platforms and "4' iuclosing the operat- 7 Anothercylindrical casing: 67', of somewhat greater diameter than the casing66, extends from the annular member 8 upward somewhat above the platform'5. casing 67 is turned in to form a flange 6'7 which is removablyclamped against the under side of the annular member 8 by screws 68. Thecasings 66 and 67 are cured together by means of one or more pipeuirconduit'membel's 69, which extend between apertures formed in thecasings 66 and .57. Air for ventilating the interior mechanism of thelamp passes through the bores of these tubular members 69.

The (liiierence in the diameters of the cusings (36 and (37 results inthe formation of an annular space or chimney through which the heatedgases or vapors from the are be- W961i the electrodes 13 and 16 canescape The lower end of the outerfrom the lamp. As is clearly shown in.Fig. l, the outer edge 1 of cap or top 1 is turned down so as to formhood which prevents moisture or dirt from entering the annular spacebetween the casings 66 and 67.

Lugs 70 which depend from the under side of the annular member 8 areformed with threaded apertures through which screws 70. pass. Thesescrews detachably secure in place a globe 71 which is formed oftransparent or translucent material. such as glass. Spaces 2 existbetween the top of the globe 71 and the annular member 8 through whichthe air ncl'zessary for the proper operation of the are may enter. Theproducts of combustion from the are, mixed with a certain amount of airwhich enters through the spaces 72, pass upward through the tubular"passage formed by the flange 8 into the space between the platform 7and the annular member 8, and thence through the annular space betweenthe casings (S6 and 67, finally leaving the lamp through the spacebetween the outer edge of the casing 67 and the cap or top 1.

Brackets 73 secured to the under side of. the cap or top 1 hold aresistance coil 7-1. A bushing 75 carried by one of the posts (3 has asliding electrical contact with the rack bar 2l'and through it With theelectrode 16.

For a proper understanding of the circuit connections of the lampreference should be had. to the diagram shown in Fig.

6. Referring to the diagram, a conductor 76 extends from the bindingpost to the lower electrode 16 of the lamp. One terminal oi the coils26, which are in series with one another, is connected to the line 76,at

the point 7TH The other terminal of the coils 26 is connectcd to thecontact member 39. One terminal of the resistance conductor 74 isconnected to the line 76 at the point 78. The other terminal of theresistance conductor 74 is connected to the plate 49 by a conductor 79.A conductor 80 couuccte, the plate 4-1 with line 7) the point 81. Aconductor connects the binding; post 3"With one terminal of the ma uetL3. A. conductor 84 connects theplate o2 with the line 82 at the point85. The other terminal of the coil 43 is connected to the plate l0 by aconductor 86.

The movable parts of the lamp mechanism are shown in the drawings anddiagram in the jiositions they occupy when the lamp is out of circuit.When the binding posts 3 and 3 are connected in a propel opera ingcircuit, currentnvill flow from the binding post 3 through the conductor82, conductor Sl, plate 52, contact member 53, plate 49, line 79 to thepo nt fill; thence the current will divide. one branch flowing throughthe resistance couductm: 74 to the line 76, and thence to terminal 2-3,and the other through the conductor 80, plate 41,

was

'As soon as the armature 'lh windings same time the contact screw 40,late 39, windings of the coils 26 through tlih line 76 to the terminal3. The passage of 'current t-hrough the windings 26 will energize themand cause them to attract the armature 30, hen the armature 30 isattracted the pawl 35 will engage the ratchet wheel 25 and rotate it inthe direction shown by the arrow in Fig. 2. Near the inner limit of themovement of the armature 80 the arm 42 will engage the plate 39 and moveit away from the contact screw 40. This will break the circuit throughthe electr0-magnets 26, which will be denergized and allow the armature80 to return to its original position. The movement of the wheel 25 inthe opposite direction to that indicated by the arrow in Fig. 2 will beprevented at this time by the dog or pawl 38.

30 moves outward the plate 3.) will by its resiliency again move intocontact with the screw 4-0, thus re'energizing the magnet coils 26. Thearmature 30 will again be attracted and the wheel 25 given a furthermovement in the direction indicated by the arrow in Fig. 2. The rotationof the ratchet wheel 25 causes a corresl'ionding rotation .of thespur-gear wheel 7 24 in a direction which elevates the rack bar 21, andconsequently the electrode 16. This intermittentenmgization of themagnet coils 26 and s'tcpdw-stcp rctation of the ratchet wheel 25 iscontinued until the elecagainst the electrode 13. current will begin toflow from the terminal 3 through the conductor 82, windings of theelectro-magncts 4-3, con ductor 86, plate 10, electrode 13, electrode16, conductor 76 to the terminal :3. The passage of current through thewindings of the clcclro-nmgnet 4- will cause it to attract the armaturell. 'hcn the armatm'e at is attracted the downward movement of its freeend moves the contact plate 52 away from the contact member 53,- Thisbl'OflhS the circuit which includes the resistance conductor Tel, andthe one which includes 01', the magnets 36. At the downward ngovcn'icntol' the rod 5 will cause the collar to move the dog 38 out of engagementwilh the ratchet whccl. In 'a similar manner-the collar 55 will engagethe cxlcnsion 237 of the arm :36 and thcrcby move the vpawl 3? out 01"cugagcmcnt with the wheel 2.7, thus 'lrceing the Wheel 3., which willbcgin lo rolalc un dcr the weight oi" the bar 21 and parts carricdlhcrcby, in a dircclion opposilc to that l indicalcd by the arrow inFig. As the l electrodes '13 and It; scparalc an arc is l drawn bctwccnthcm the rod 51 begins l to descend the collar til will movc away fromthe pawl 58 which will lhcrcby clamp l the rod 56 between it and theyolcc member 57. Allcr a movement ol' the rod :"lfitequal i to the playof the pawl 58 between the coltrode lo. strikes \Vhcn this occurs larsand 61, the collar 60 will strike against the upper end of the pawl'58-As this engagement operates to more firmly force the inner end of thepawl 58 into engagement with the rod 59, the downward movement of therod 59, and thereby of the electrode 16, is checked. It will thus bereadily seen that the separation of the electrodes 13 and 16 occurringafter their contact is always equal to the play of the pawl 58 betweenthe collars and 61, and in consequence the are struck after each feedinoperation with any given adjustment of the collars 60 and 6] is alwaysof a constant length. llhen the How of the current through the windingsof the clectro-magnet 43 is interrupted in any ture 44 will be movedupward by the spring 46, allowing the spring contact 52 to engage thecontact member 53. If after or at the time at which this occurs theterminals 3 and. 3 are connected in a suitable circuit theelectromagnets 26 will be energized and deenergized in the mannerhcreinbefore described until the electrodes 13 and 16 again engage. Asthe rod 55) moves up, the collar (51 will engage the under side of thecarry it and the yoke member 57 upward a distance equal to thedill'erence between the distance separating the ends of the electrodes13 and 16 at the beginning of the feeding operation and the player thepawl 58 through the collars 60 and (31. .When currentbcgins to flowagain through the windings ot' the electro-magnct 43 the armature 44will again be attracted and the electrodc 16 will again separate fromthe cleclrode 1:3 drawing an arc of a predetermincd length. i i

ll. hasbeen trodc 16 can be employed in character which wastes away soslowly that a .lccding operation of the lamp is not required durim thenormal period of operalion. lien, however, it becomes necessary ordesirable to employ a, lamp in. which the electrode may be led atintervals as it wastes away. it is only necessary to employ means forslim-t-(.'i1'cuiting or otherwise decnergizing the windings of theelectro-magnet 43 whenever a feeding operation is neccssanv.

Most of the products 'ofcombustion from the are between the electrodes13 and 16 are carricd "up by the draft created by the heat of the arcthrough the tubular member 8' into the space between the platform 7 andthe annular member 8, and thence through the annular space bctwccn thecaslugs (to and (l? and the lamp when they are discharged into the atmospherc through the space between the end of the casing (57 and thecap. The casing :=li(ll members (ill and (37 may be regarded as harminga (llllll)l(\--\\'2lll((l vcrlical annular manner the armapawl 58 andfound that a consuming eleclamps of this upper end of the i casing.- Thespace or chamber between the walls this casing forms achimney pas sagethrough which the are products are carried by natural drafts. The member7 forms a horizontal partition which prevents the are products frompassing'into the space in which the electrodemoving mechanism islocated. e

More or less of the products of the arc may, condense upon the interiorparts of the lamp. In order to remove this condensed deposit the screws68 may be loosened and the casing 66and 67 removed from the lamp,whereupon the various parts of the lamp may be -readily cleaned.

I have found that where the positive electrode is formed out of anyconducting material,v stich as copper or the like, in order to revent arapid destruction of the electrode y oxidization or otherwise, it isnecessary that the electrode be so arranged that it will not be heatedto too high a temperature by the arc.

In the'lamp h'ereinbefore described and illustrated I have formed-thepositive electrode 13 out of a copper pencil or rod con- 'nected to aplate also made of copper or other material which is agood conductor ofheat. In consequence of this the heat generated at the arc end of thepencil is rapidly conducted along the lcngthof the pencil to the plate10. As the plate 10 has avery considerable heat-radiating or dissipatingcapacity the heat which is thus conducted away from the pencil 13 to theplate 10 is rapidly dissipated. This insures the temperature of thepencil 13 being maintained at a much lower point than would be the caseif the plate 10, which is both a good conductor and a good radiator ofheat, were not employed; The heatgdissipating-capacity of the electrodeshould not, however, be ,;.:'jncrcased beyond certain limits, at leastwith many substances which may be employed in the consuming negativeelectrode, as they give off fumes which will condense m large amountsupon the positivcelectirodc if it is too cool. These fumesare in manycases more or less non-conducting and when condensed on the electrodeinterfere in various ways with the proper operation of the lamp. Itwillof course be understood that the pen- ('il 1? and plate 10 connectedthereto is only one form of non-consuming electrode having a properheat-dissipating capacity and that this feature of my invention can beembodied in other forms.

of the pencil which is but poorly conducting The annular space 15 formedat the lower,

endof the positive electrode between the pencil 13 and insulating jacket15 is of advantage as it prevents the formation of a slag which mightotherwise be created and which might cause the agglomeration of the endof the pencil and jacket along. with some of the material condensed fromthe arc.

While I have hereinbefore described and illustrated in detail oneembodiment of my invention, it is not intended that my invention shallbe limited to this particular embodiment'as it will be apparent to anyone skilled in the art that many changes may be made in the form of myinvention without departing from its spirit.

What I claim as new and desire'to secure by Letters Patent of the UnitedStates, is,

1. In an arc lamp, a movable electrode, a feeding mechanism thereforcomprising a member moving with said electrode, a stationary rod orpost, a clutch includin a yoke surrounding said rod or post, an a pawlnormally engaging, said rod and ex tending between stops carried by saidmember whereby a predetermined movement of the'member in one directioncauses a corresponding movement of the clutch relative to the post andthe clutch serves to limit the movement of the member in the'oppositedirection, and manually actuated means for. moving said clutchrelative to said rod in the direction opposite to that in which theclutch is moved by saidmember.

2.. In an arc lamp, an electrode feeding mechanism comprising a rod orbar, an arc length limiting clutch mounted thereon and normally freeto/move in one direction only, and means for engaging said clutch tomove it in the oposite direction.

3. In a are lamp, a rod or bar. a clutch comprising a yoke surroundingsaid rod or bar','"hnd a pawl pivoted to the yoke, means for engagingone end of the pawl. to release the clutch from the rod to move it inone; direction, and means fur engaging the yoke to move the clutch inthe opposite direction.

4. In an arc lamp, an arc length limiting clutch, a member upon which itismonntcd. a connection between the clutch and the feed mechanism of thelamp whereby the movement of the feed mechanism in one direction willmove the clutch with it. while a predetermined movement of the feedmechanism in the otherdirection will cause the clutch to engage thesupporting member and limit the movement of the feed mechanism in saidopposite direction, and means for rendering the engagement between theclutch and the supporting member inoperative.

5. In an arc lamp, a pair of electrodes, a feeding mechanism thereforcomprising a movable rack bar, an electrode moving with said rack bar, asecond electrode, a gear wheel engaging saidrack bar to move it and theWinding of which is in series with said the action of gravity,- anintermittently actu- 111g means are rendeied inoperative. artedelectromagnet for rotating saidgear In witness whereof, I have hereuntoset wheel, means connecting said electromagnet my hand this 7th day ofNovember, 1903.

JOHN T. H, DEMPSTER.

thereby move the electrodes together against novement of the raelgbarafter said connect-- l0 electrode and said gear Wheel, means actu- Iated by the passage of current between the W1tnesses: electrodes forrendering said connectlng Ii means inoperative, and means limiting theHELEN ORFORD.

BENJAMIN B. HULL, i

